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Laser Capture (laser + capture)

Distribution by Scientific Domains
Medical Sciences50%
Life Sciences50%

Terms modified by Laser Capture

  • laser capture microdissection
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    Selected Abstracts

    Decreased expression of thymidine phosphorylase/platelet-derived endothelial cell growth factor in basal cell carcinomas

    EXPERIMENTAL DERMATOLOGY, Issue 11 2008
    Pierre E. Stoebner
    Abstract:, Thymidine phosphorylase (TP)/platelet-derived endothelial cell growth factor is associated with tumor angiogenesis. We evaluated the TP mRNA and protein expression in basal cell carcinomas (BCC) and in various skin tumors including numerous BCC histological simulants. Immunohistochemistry was performed on 99 paraffin sections of formalin-fixed skin tumors using monoclonal antibodies (mAb) against TP. TP mRNA levels were measured by real time RT-PCR in whole BCCs (wBCC) and laser capture microdissected (LCM) BCC tumor cells. TP immunostaining was negative in all BCC variants and in most of the benign trichogeneic tumors studied. By contrast, TP was constantly immunodetected in actinic keratosis (AK), squamous cell carcinomas (SCC), syringomatous carcinomas (SC), basosquamous carcinomas (BSC) and melanomas. TP mRNA levels were low and statistically not different in wBCC and normal skin but were strongly downregulated in LCM-BCC as compared with LCM-normal epidermis. We concluded that (i) anti-TP mAb is an useful marker to differentiate BCC from AK, SCC, BSC and SC but not from trichoblastic tumors, (ii) the lack of TP protein expression in BCC tumoral cells is linked to transcriptional regulatory mechanisms, (iii) the low TP mRNA levels in whole BCC may be related to the low intra-tumoral microvessel density, the slow growth and the very low metastatic potential of these tumors. [source]

    Multi-site genetic modification of monolignol biosynthesis in alfalfa (Medicago sativa): effects on lignin composition in specific cell types

    NEW PHYTOLOGIST, Issue 3 2008
    Jin Nakashima
    Summary ,,Independent antisense down-regulation of 10 individual enzymes in the monolignol pathway has generated a series of otherwise isogenic alfalfa (Medicago sativa) lines with varying lignin content and composition. These plants show various visible growth phenotypes, and possess significant differences in vascular cell size and number. ,,To better understand the phenotypic consequences of lignin modification, the distributions of lignin content and composition in stems of the various alfalfa lines at the cellular level were studied by confocal microscopy after staining for specific lignin components, and by chemical analysis of laser capture dissected tissue types. ,,Although all antisense transgenes were driven by the same promoter with specificity for vascular, fiber and parenchyma tissues, the impact of down-regulating a specific transgene varied in the different tissue types. For example, reducing expression of ferulate 5-hydroxylase reduced accumulation of syringyl lignin in fiber and parenchyma cells, but not in vascular elements. ,,The results support a model for cell type-specific regulation of lignin content and composition at the level of the monolignol pathway, and illustrate the use of laser capture microdissection as a new approach to spatially resolved lignin compositional analysis. [source]

    Selective over-expression of fibroblast growth factor receptors 1 and 4 in clinical prostate cancer,

    THE JOURNAL OF PATHOLOGY, Issue 1 2007
    K Sahadevan
    Abstract Fibroblast growth factor receptors (FGFRs) mediate the tumourigenic effects of FGFs in prostate cancer. These receptors are therefore potential therapeutic targets in the development of inhibitors to this pathway. To identify the most relevant targets, we simultaneously investigated FGFR1,4 expression using a prostate cancer tissue microarray (TMA) and in laser capture microdissected (LCM) prostate epithelial cells. In malignant prostates (n = 138) we observed significant FGFR1 and FGFR4 protein over-expression in comparison with benign prostates (n = 58; p < 0.0001). FGFR1 was expressed at high levels in the majority of tumours (69% of grade 3 or less, 74% of grade 4 and 70% of grade 5), while FGFR4 was strongly expressed in 83% of grade 5 cancers but in only 25% of grade 1,3 cancers (p < 0.0001). At the transcript level we observed a similar pattern, with FGFR1 and FGFR4 mRNA over-expressed in malignant epithelial cells compared to benign cells (p < 0.0005 and p < 0.05, respectively). While total FGFR2 was increased in some cancers, there was no association between expression and tumour grade or stage. Transcript analysis, however, revealed a switch in the predominant isoform expressed from FGFR2IIIb to FGFR2IIIc among malignant epithelial cells. In contrast, protein and transcript expression of FGFR3 was very similar between benign and cancer biopsies. The functional effect of targeting FGFR4 in prostate cancer cells has not previously been investigated. In in vitro experiments, suppression of FGFR4 by RNA interference effectively blocked prostate cancer cell proliferation (p < 0.0001) and invasion (p < 0.001) in response to exogenous stimulation. This effect was evident regardless of whether the cells expressed the FGFR4 Arg388 or Gly388 allele. In parallel experiments, FGFR3 suppression had no discernible effect on cancer cell behaviour. These results suggest evidence of selective over-expression of FGFR1 and FGFR4 in clinical prostate cancer and support the notion of targeted inhibition of these receptors to disrupt FGF signalling. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source]

    Detection of Hypoxia Inducible Factors and Angiogenic Growth Factors during Foetal Endochondral and Intramembranous Ossification

    ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 4 2010
    W. De Spiegelaere
    With 6 figures and 1 table Summary During skeletogenesis, the development of a new vascular network, i.e. angiogenesis, is triggered by hypoxia through the activation of the hypoxia inducible factors (HIFs) HIF-1, and HIF-2,. HIFs regulate the expression of several genes, including those coding for angiogenic growth factors such as VEGFA, angiopoietin-1 (ANGPT1) and angiopoietin-2 (ANGPT2). The expression of HIFs and angiogenic growth factors is well documented in endochondral ossification, but few data exist on their expression during intramembranous ossification. In this study, the localization of these factors was examined using immunohistochemistry and RT-PCR in bones of porcine foetuses. Immunostaining for HIF-1, and HIF-2, was observed during endochondral ossification, whereas only HIF-2, was present at sites of intramembranous ossification. Furthermore, immunostaining for ANGPT2 was present at sites of endochondral and intramembranous ossification. In addition, gene transcripts for ANGPT1, ANGPT2 and VEGFA were detected with RT-PCR in laser capture microdissected isolates from both types of ossification. These results indicate that angiogenesis plays an important role during endochondral and intramembranous ossification. However, the different expression pattern of the HIF-, subunits suggests that alternative regulatory pathways trigger angiogenesis in these distinct types of ossification. [source]